Computer architecture simulation has always played a pivotal role in continuous innovation of computers. However, constructing or modifying a high quality simulator is time consuming and error-prone. Thus, often Architecture Description Languages (ADLs) are used to provide an abstraction layer for describing the computer architecture and automatically generating corresponding simulators. Along the line of such research, we present a novel XML-based ADL, its compiler, and a generation methodology to automatically generate multithreaded simulators for computer architecture. We utilize the industry-standard extensible markup language XML to describe the functionality and architecture of a modeled processor. Our ADL framework allows users to easily and quickly modify the structure, register set, and execution of a modeled processor. To prove its validity, we have generated several multithreaded simulators with different configurations based on the MIPS five-stage processor, and successfully tested with two programs.